Skip with hydraulically operated dumping door



Oct. 30, 1962 J. w. CLARK 3,061,128

SKIP wxm HYDRAULICALLY OPERATED nuwmc DOOR Filed Dec. 22, 1959 2 Sheets-Sheet 1 INVENTOR. JAMES W.C.LP\P-K BY l ATTORNEY Oct. 30, 1962 J. w. CLARK SKIP WITH HYDRAULICALLY OPERATED DUMPING DOOR 2 Sheets-Sheet 2 Filed Dec. 22, 1959 INVENTOR. JAMES W. CLARK ATToRNGJY United States Patent 3,061,128 SKIP WITH HYDRAULICALLY OPERATED DUMPIN G DOOR James W. Clark, Iron Mountain, Mich., assignor to Lake Shore, Inc., Iron Mountain, Mich., a corporation of Michigan Filed Dec. 22, 1959, Ser. No. 1,153 18 Claims. (Cl. 214-741) This invention relates to skips and particularly to a front discharge skip having a hydraulically operated dumping door. I

-It is an object of this invention to provide a skip which can be quickly dumped while remaining in the guide timbers and which can be dumped with a minimum of stress being transferred to the head frame.

Another object is to provide a skip having means for adjusting the door actuating mechanism so that the size f the discharge opening can be pre-set.

Another object is to provide a skip having a smooth operating dumping door actuating mechanism with a positive door opening and closing action which Will not be damaged if the door becomes jammed for any reason.

The objects of this invention are attained by a skip having a skip body with a discharge opening in the front wall of the body and a dumping door slidably mounted for movement across the discharge opening. A hydraulic door operating mechanism is mounted in a recess in the front wall of the skip body above the door and is adapted when actuated to open and close the door with a positive action. An actuator means including a conventional dump roller on the skip and a scroll in the headframe is provided for actuating the door operating mechanism to thereby open and close the door in response to the normal travel movement of the skip.

The hydraulic operating mechanism includes a power cylinder having a piston adapted for actuation by the actuator means and a door actuating cylinder having a piston operatively connected to the dumping door. The power and door actuating cylinders are interconnected by fluid pressure lines so that when the power piston is actuated by the actuator means the door actuating piston will be actuated to open and close the dumping door.

An adjustment means is provided for regulating the amount the dumping door will be opened when the skip is hoisted into the headframe for dumping. Such adjustment means includes a bypass conduit between the fluid pressure lines for bypassing the door actuating cylinder. A bypass valve is mounted in the bypass conduit and is adapted when opened to bypass flow around the door actuating cylinder and thus stop the opening movement of the door. The bypass valve is actuated by an adjustable cam which can be set to open the bypass valve at a plurality of preselected positions of the actuator means as the skip is hoisted into the headframe.

To prevent damage to the equipment if the door becomes jammed by a rock for example, I provide a pressure relief valve mounted in a conduit which bypasses the door actuating cylinder. Thus, when the pressure in the system reaches a predetermined maximum, the pressure relief valve will open and bypass the door actuating cylinder until the trouble is remedied.

A further refinement of the invention is the provision of an accumulator tank for the system which can be pressurized from a source of compressed air for example to provide reserve power for the system and a cushion for the operation of the hydraulic cylinders. The accumulator also serves to accommodate excess fluid which may result from a differential in cylinder size and the operation of the door opening adjustment means described above.

.Other objects and advantages will be pointed out in or 3,il5l,l28 Patented Oct. 30, 1962 ice be apparent from the specification and claims, as will obvious modifications of the single embodiment shown in the drawings of which:

FIG. 1 is a fragmentary front elevation of a skip embodying my invention with some parts broken away;

FIG. 2 is a fragmentary side elevation of the skip shown in FIG. 1 with some parts broken away;

FIG. 3 is a view similar to FIG. 2 but with the door opened; i

FIG. 4 is a sectional view taken along line 4-4 of FIG. 1;

FIG. 5 is a view taken along line 5-5 of FIG. 4; and

FIG. 6 is a sectional view taken along line 66 of FIG. 1.

Referring to the drawings in detail, the skip comprises a body 10 supported in a mine shaft by a wire rope. The skip is guided in the shaft in a conventional manner by guide timbers (not shown) mounted in the shaft and engaged by rollers (not shown) mounted on stringers 11 fastened to the skip body. Body 10 has an open top for filling and a bottom 12 which slopes to a discharge opening 13 in the front face of the body.

The skip has a dumping door or gate 14 slidably mounted in guides 15 by rollers 16 (FIG. 6) for vertical movement between a closed position (FIGS. 1 and 2) and an open position (FIG. 3). A door operating mechanism 17 for opening and closing door 12 is mounted in a recess 18 in the front face of the skip body above the door. Mechanism 17 is actuated as the Skip moves in the guide timbers by a pair of dump rollers 19 adapted to work within a pair of dump scrolls 20 mounted in the headframe of the mine and located in the path of movement of the rollers.

Door actuating mechanism 17 includes a pair of hydraulic power cylinders 22 having pistons 24 (shown in dotted lines) with piston rods 26 pivotally connected to the skip body by brackets 28 (FIGS. 1 and 3). Pistons 24 in cylinders 22 are actuated by the action of dump rollers 19 Working within scrolls 20 as the skip is hoisted into the headframe. Rollers 19 are mounted on side skirts 30 of a plate-like dumping member 32 which is pivotally mounted in the upper end of recess 18 by a shaft 34. In the closed position (FIGS. 1 and 2) member 32 and skirts 30 serve to enclose and protect door actuating mechanism 17 in recess 18. The upper ends of power cylinders 22 are pivotally fastened to member 32 by brackets 36 so that when rollers 19 enter the scrolls member 32 Will be pivoted outwardly causing cylinders 22 to be pulled upwardly and pivoted outwardly from the position shown in FIG. 2 to that shown in FIG. 3. This movement causes pistons 24 to be actuated downwardly in cylinders 22 to thereby force hydraulic fluid from the cylinders through fittings 40 and flexible hoses 42 to an opening manifold 44 mounted in the upper portion of recess 16. From opening manifold 44 the fluid flows into the bottom of a stationary door actuating hydraulic cylinder 46 through hoses 48 and a fitting 50. Cylinder 46 is fixedly mounted in the central portion of recess 18 between power cylinders 22 and has a piston 52 (shown in dotted lines) with a connecting rod 54 connected to the top of dumping door 14 by a bracket 56. Thus, when pistons 24 of power cylinders 22 are actuated by the action of rollers 19 working in scrolls 20, hydraulic fluid is forced from the power cylinders to the bottom of door actuating cylinder 46 to thereby force piston 52 upwardly causing door 14 to open (FIG. 3) and dump the contents of the skip.

As shown in FIG. 1, the top of cylinder 46 communicates with the top of cylinders 22 by means of a fitting 58 at the top of cylinder 46, hoses 60, a closing manifold 62, hoses 64 and fittings 66 at the top of cylinders 22. The hydraulic system is completely filled with fluid so that when piston 52 is raised due to the opening movement of cylinders 22, fluid will be forced into the top of the power cylinders above pistons 24. Thus, when skip body 10 is lowered from the headframe cylinders 22 to return to the position shown in FIG. 2, the flow of fluid in the system will be reversed causing door 14 to be closed by the positive force exerted on the top of piston 52 in door actuating cylinder 46.

' Thus, it is seen that with a door operating mechanism 17 of the type described above the dumping door 14 will be both opened and closed with a positive action by virtue of the double-acting hydraulic cylinders 22 and 24. The mechanical advantage gained by the use of the hydraulic cylinders permits the door to be opened and closed with a relatively small force at the dump rollers and thus keeps the stresses exerted on the headframe and guide timbers to a minimum.

To prevent damage to the system a pressure relief valve 68 is provided in a conduit 70 between door opening and closing manifolds 44 and 62, respectively. Thus, if the door becomes jammed by a rock when closing, for example, valve 68 will open and bypass the door actuating cylinder 46 to prevent damage to the equipment. Valve 68 is double-acting so that it will operate to relieve the system should trouble occur when mechanism 17 is moving in either the door opening or closing directions.

Another feature of the invention is the provision of an adjustment means 72 (FIGS. 4 and for presetting the amount door 14 will be opened when the skip is hoisted into the headframe. Adjustment means 72 includes a pair of bypass conduits 74 between door opening and closing manifolds 44 and 62, respectively, each having a bypass valve 76 mounted therein. Valves 76 are actuated to open and bypass door actuating cylinder 46 at preselected door opening positions by adjustable cam members 77 rotatably mounted on shaft 34. Members 77 can be rotatably positioned and locked with respect to shaft 34 by spring loaded pins 78 mounted on flanges 88 fixed to the shaft and adapted to engage spaced openings 82 in members 77 in any one of a plurality of different angular positions. The bypass valves '76 are actuated by earns 77 by follower arms 84 pivotally mounted on brackets 86 by pins 8% as clearly shown in FIG. 4. Thus, it is seen that by adjusting the position of cam member 77 on shaft 34, valves 76 can be actuated at any one of several positions of member 32 as it is swung outwardly from the skip by the action of rollers 19 working in scrolls 20. Once valves 76 are opened to bypass cylinder 46 no further movement of door 14 will occur thus making it possible to control the size of the discharge opening when dumping.

As shown best in FIG. 1, an accumulator 90 is connected to door opening manifold 44 by a conduit 92. The accumulator performs several functions. It serves as a sump to supply hydraulic fluid to the system to replenish fluid lost due to leakage, etc. and to accommodate excess fluid due to differences in the displacement of the cylinders because of size and because of the operation of adjustment means 72. The accumulator also provides a convenient place to pressurize the system from an outside source of power to provide an operating cushion and reserve power to insure positive action at the dumping door. In the preferred embodiment the pressure in accumulator 90 is maintained at 50 psi. by a compressed air line 94 (FIG. 1).

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. A skip comprising, a skip body having a discharge opening in the front wall of said skip, a dumping door slidably mounted for movement across 'said discharge opening, hydraulic door operating mechanism mounted on said skip and adapted when actuated to open and close said door with a positive action, actuator means adapted to actuate said operating mechanism to open and close said door in response to the normal travel movement of said skip, said hydraulic operating mechanism including a power cylinder having a piston adapted for actuation by said actuator means, a door actuating cylinder having a piston operatively connected to said dumping door, and fluid pressure lines interconnecting said power and door actuating cylinders so that when said power piston is actuated said door actuating piston will be actuated to open and close said door with a positive action, and means for adjusting the distance said door will be opened by said door actuating piston when said power piston is actuated by said actuator means in response to the normal travel movement of said skip.

2. A ski according to claim 1 in which said adjustment means includes a bypass conduit means between said fluid pressure lines bypassing said door actuating cylinder and a bypass valve mounted in said bypass conduit means and adapted when opened to bypass said door actuating cylinder.

3. A skip according to claim 2 in which said adjustment means further includes an adjustable cam means actuated by said actuator means and adapted to open said bypass valve at a plurality of preselected positions of said actuator means as it moves in response to the normal travel movement of the skip.

4. A skip according to claim 1 in which said hydraulic operating mechanism includes an accumulator tank connected to said power and door actuating cylinders, said tank being pressurized from a source outside the system.

5. A skip comprising, a skip body having a discharge opening in the front Wall of said skip, a dumping door slidably mounted for movement across said discharge opening, a door actuating cylinder mounted on said skip and having a piston operatively connected to said dumping door, a power cylinder mounted on said skip and having a piston adapted when actuated to energize said door actuating cylinder to open and close said door, a dumping member pivotally mounted on said skip body and adapted when pivoted to actuate said power piston of said power cylinder, and actuator means adapted to actuate said dumping member to open and close said door by the normal travel movement of said skip.

6. A skip according to claim 5 in which said actuator means includes a dump roller mounted on said dumping member and adapted to work within a stationary dump scroll during the normal travel movement of the skip to thereby pivot said member and open and close said door.

7. A skip according to claim 5 in which said power and door actuating cylinders are mounted in a recess in the front face of said skip body above said door, said dumping member serving as a cover for said recess to enclose said cylinders when said door is closed.

8. A skip comprising, a skip body having a discharge opening in the front wall of said skip, a dumping door slidably mounted for movement across said discharge opening, a hydraulic door actuating cylinder mounted on said skip and having a piston operatively connected to said door, a hydraulic power cylinder mounted on said skip and having a piston, said power and door actuating cylinders having fluid pressure lines interconnecting said cylinders so that when said power piston is actuated said door actuating piston will be actuated to open and close said door, a dumping member pivotally mounted on said skip body and operatively connected to said power cylinder, said dumping member adapted when pivoted to actuate said power piston to open and close said door, actuator means adapted to actuate said dumping member to open and close said door by the normal travel movement of said skip, and means for adjusting the distance said door will be opened by said door actuating piston when said power piston is actuated by said actuator means in response to the normal travel movement of said skip.

9. A skip according to claim 8 in which said adjustment means includes a bypass conduit means between said fluid pressure lines bypassing said door actuating cylinder and a bypass valve in said bypass conduit means adapted when opened to bypass said door actuating cylinder.

10. A skip according to claim 9 in which said adjustment means further includes an adjustable cam means actuated in response to the pivotal movement of said dumping member and adapted to open said bypass valve at a plurality of preselected positions of said dumping member as it is actuated by said actuator means.

11. A skip according to claim 10 in which said adjustable cam means includes a cam member rotatably mounted on said dumping member and adapted for locking engagement with said member at a plurality of different angular positions.

12. A skip according to claim 8 in which said power and door actuating cylinders are mounted in a recess in the front face of said skip body above said door, said dumping member serving as a cover for said recess to enclose said cylinders when said door is closed.

13. A skip comprising, a skip body having a discharge opening in the front wall of said skip, a dumping door slidably mounted for movement across said discharge opening, a hydraulic door actuating cylinder mounted on said skip and having a piston operatively connected to said door, a hydraulic power cylinder having a piston, said power and door actuating cylinders having fluid pressure lines interconnecting said cylinders so that when said power piston is actuated said door actuating piston will be actuated to open and close said door, a dumping member pivotally mounted on said skip body and operatively connected to said power cylinder, said dumping member adapted when pivoted to actuate said power piston to open and close said door, actuator means adapted to actuate said dumping member to open and close said door by the normal travel movement of said skip, and safety means for preventing damage to the equipment in case said door or other mechanism becomes jammed, said safety means including a bypass conduit means between said fluid pressure lines bypassing said door actuating cylinder and a pressure relief valve mounted in said bypass conduit means adapted to open and bypass said door actuating cylinder when pressure in the system reaches a predetermined maximum.

14. A skip comprising, a body having a discharge opening therein, a dumping door mounted at said discharge opening and adapted for movement between an open and closed position, hydraulic door opera-ting means mounted on said skip and operatively connected to said dumping door, said hydraulic door operating means adapted when mechanically actuated to open and close said door with a positive action, and actuator means operatively connected to said hydraulic door operating means and adapted when actuated to mechanically actuate said hydraulic door operating means to thereby open and close said door, said actuator means including a dumping member pivotally mounted on said skip and operatively connected to said hydraulic door operating means, said dumping member adapted for actuation by the normal travel movement of 6 said skip to thereby actuate said hydraulic door operating means.

15. A skip comprising, a skip body having a discharge opening in the front wall of said skip, a dumping door adapted for movement between an open and a closed position, hydraulic door operating mechanism carried by said skip and adapted when actuated to open and close said door with a positive action, an actuator means adapted to actuate said operating mechanism to open and close said door in response to the normal travel movement of said skip, said hydraulic operating mechanism including a power cylinder operatively connected to said actuator means and a door actuating cylinder operatively connected to said door, said power cylinder adapted to energize said door actuating cylinder to open and close said door when said power cylinder is actuated by said actuator means, one end of said power cylinder being pivotally connected to said skip body for swinging movement outwardly from said body when actuated by said actuator means.

16. A skip according to claim 15 in which said power cylinder is operatively connected to said actuator means by a dumping member pivotally mounted on said body, said member being pivotally connected to the other end of said power cylinder so that when said member is pivoted by said actuator means said power cylinder will be actuated to thereby energize said door actuating cylinder.

17. A skip according to claim 16 in which said actuator means includes a dump roller mounted on said dumping member and adapted to work within a stationary dump scroll during the normal travel movement of the skip to thereby pivot said member and open and close said door.

18. A skip comprising, a skip body having a discharge opening in the front wall of said skip, a dumping door adapted for movement between an open and a closed posi tion, hydraulic door operating mechanism carried by said skip and adapted when actuated to open and close said door with a positive action, and actuator means adapted to actuate said operating mechanism to open and close said door in response to the normal travel movement of said skip, said hydraulic operating mechanism including a power cylinder operatively connected to said actuator means, and a door actuating cylinder operatively connected to said door, said power cylinder adapted to energize said door actuating cylinder to open and close said door when said power cylinder is actuated by said actuator means, said hydraulic operating mechanism further including an accumulator tank connected to said power and door actuating cylinders, said tank being pressurized from a source outside the system.

References Cited in the file of this patent FOREIGN PATENTS 778,826 France Jan. 2, 1935 731,941 Great Britain June 15, 1955 565,627 Belgium Mar. 31, 1958 71,075 France Mar. 23, 1959 

